Java is the name of an object-oriented programming language developed by Sun Microsystems. It uses syntax similar to the C++ programming language, but is more portable (i.e. it is easier to run programs written in it, on different types of computer or operating system), and is more robust (i.e. it promotes better use of proper object-orientated techniques and prohibits techniques that often lead to inferior quality software).

The phrase "Java" is also used to refer to the Java platform, which is comprised of the JDK used to develop Java programs, and the JRE use to run Java programs. There are three distinct flavours of Java platform:

• J2SE - Used to develop stand-alone desktop programs, and applets that run in web-browsers
• J2ME - Used to develop programs for small embedded devices, i.e. mobile phones
• J2EE - Used to develop distributed enterprise enterprise systems, e.g. in e-commerce

Each type of Java platform is associated with a wide range of libraries that provide re-usable 'classes' that to make program development easier. Learning Java normally means not just learning the language syntax and semantics, but also learning about the relevant Java platform and its libraries.

The following table summarises some of the main advantages of disadvantages of Java over C++ that are often asserted:

Write-once, run anywhere
Purer object orientation
Stronger data-type enforcement
Safe memory management
Still evolving

Hard to develop programs that use OS-specific features
Can be lower performance
Not an open standard